1. Field of the Invention
The present invention relates to an image reading apparatus and, more particularly, to an image reading apparatus for a contact image sensor module which is easy to disassemble, has low cost and is recyclable.
2. Description of the Related Art
Contact image sensor modules (CISM) are typically found in standard or professional scanners, copying machines and fax machines and are used to read and output image data. As shown in FIG. 1, generally, the image reading apparatus 100 comprises a housing 110, a rod lens array 120, a light module 130 (including a light source 134, a light guide 132, light source guide terminals 136 and a white reflective housing) and a sensor board 140. In operation, it uses an edge lighting method to transform the light from the light source 134 into a stream light source via the light guide 132 and the white reflective housing outside of the light guide 132. The light is injected onto the scanned object, and reflected light passes through the rod lens array 120 for image formation so that the light is collected onto a light sensor element 142 and translated into pixel data via a photoelectric signal transformation. During assembly of the CISM, the light module 130 and the rod lens array 120 are usually glued onto the housing 110, and the sensor board 140 and the light source guide terminals 136 are welded together. With reference to FIG. 2, in the prior art assembly process for the sensor board 140, a thermal melting rod 112 disposed on the bottom of the housing 110 is placed through a hole 144 on the sensor board 140, and the thermal melting rod 112 is deformed by a hot press process to combine together the housing 110 and the sensor board 140. Please refer to FIG. 3. FIG. 3 is a schematic drawing for combining together the sensor board 140 and the light source guide terminals 136 in the prior art image reading apparatus. The light source guide terminals 136 are placed through the sensor board 140, and the two are welded together to form an electrical connection.
However, after completing the assembly process for the CSIM, if the module is of poor quality and one of the elements needs to be replaced or reworked, the above-mentioned welding and gluing bonding methods make it difficult to disassemble the elements and may lead to damage to the original elements, which wastes resources and leads to higher costs. Furthermore, the welding and gluing bonding methods require an extra welding and gluing process and related materials, which again increase both the complexity and costs. Moreover, in order to cure the bonding glue for subsequent processes, the module may need to be air dried or baked, which also increases the manufacture time and costs. When the sensor board 140 must be changed, the thermal melting rod 112 on the housing 110 needs to be broken, which may cause damage to the housing 110 and to other combined elements.
Therefore, it is desirable to provide an image reading apparatus which is designed for easy assembly and disassembly, which reduces manufacturing costs and reworking costs, and which also recycles materials to mitigate and/or obviate the aforementioned problems.